// Copyright 2010 Christophe Henry
// henry UNDERSCORE christophe AT hotmail DOT com
// This is an extended version of the state machine available in the boost::mpl library
// Distributed under the same license as the original.
// Copyright for the original version:
// Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed
// under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

#include <iostream>
// back-end
#include <boost/msm/back/state_machine.hpp>
//front-end
#include <boost/msm/front/state_machine_def.hpp>


namespace msm = boost::msm;
namespace mpl = boost::mpl;

namespace
{
	// events
	struct play {};
	struct end_pause {};
	struct stop {};
	struct pause {};
	struct open_close {};

	// A "complicated" event type that carries some data.
	enum DiskTypeEnum
	{
		DISK_CD=0,
		DISK_DVD=1
	};
	struct cd_detected
	{
		cd_detected(std::string name, DiskTypeEnum diskType)
			: name(name),
			disc_type(diskType)
		{}

		std::string name;
		DiskTypeEnum disc_type;
	};

	// front-end: define the FSM structure 
	struct player_ : public msm::front::state_machine_def<player_>
	{
		template <class Event,class FSM>
		void on_entry(Event const& ,FSM&) 
		{
			std::cout << "entering: Player" << std::endl;
		}
		template <class Event,class FSM>
		void on_exit(Event const&,FSM& ) 
		{
			std::cout << "leaving: Player" << std::endl;
		}

		// The list of FSM states
		struct Empty : public msm::front::state<> 
		{
			// every (optional) entry/exit methods get the event passed.
			template <class Event,class FSM>
			void on_entry(Event const&,FSM& ) {std::cout << "entering: Empty" << std::endl;}
			template <class Event,class FSM>
			void on_exit(Event const&,FSM& ) {std::cout << "leaving: Empty" << std::endl;}
		};
		struct Open : public msm::front::state<> 
		{	 
			template <class Event,class FSM>
			void on_entry(Event const& ,FSM&) {std::cout << "entering: Open" << std::endl;}
			template <class Event,class FSM>
			void on_exit(Event const&,FSM& ) {std::cout << "leaving: Open" << std::endl;}
		};

		// sm_ptr still supported but deprecated as functors are a much better way to do the same thing
		struct Stopped : public msm::front::state<> 
		{	 
			template <class Event,class FSM>
			void on_entry(Event const& ,FSM&) {std::cout << "entering: Stopped" << std::endl;}
			template <class Event,class FSM>
			void on_exit(Event const&,FSM& ) {std::cout << "leaving: Stopped" << std::endl;}
		};

		struct Playing : public msm::front::state<>
		{
			template <class Event,class FSM>
			void on_entry(Event const&,FSM& ) {std::cout << "entering: Playing" << std::endl;}
			template <class Event,class FSM>
			void on_exit(Event const&,FSM& ) {std::cout << "leaving: Playing" << std::endl;}
		};

		// state not defining any entry or exit
		struct Paused : public msm::front::state<>
		{
		};

		// the initial state of the player SM. Must be defined
		typedef Empty initial_state;

		// transition actions
		void start_playback(play const&)       { std::cout << "player::start_playback\n"; }
		void open_drawer(open_close const&)    { std::cout << "player::open_drawer\n"; }
		void open_drawer2(open_close const&)    { std::cout << "player::open_drawer2\n"; }
		void close_drawer(open_close const&)   { std::cout << "player::close_drawer\n"; }
		void store_cd_info(cd_detected const&) { std::cout << "player::store_cd_info\n"; }
		void stop_playback(stop const&)        { std::cout << "player::stop_playback\n"; }
		void pause_playback(pause const&)      { std::cout << "player::pause_playback\n"; }
		void resume_playback(end_pause const&)      { std::cout << "player::resume_playback\n"; }
		void stop_and_open(open_close const&)  { std::cout << "player::stop_and_open\n"; }
		void stopped_again(stop const&)	{std::cout << "player::stopped_again\n";}
		// guard conditions
		bool good_disk_format(cd_detected const& evt)
		{
			// to test a guard condition, let's say we understand only CDs, not DVD
			if (evt.disc_type != DISK_CD)
			{
				std::cout << "wrong disk, sorry" << std::endl;
				return false;
			}
			return true;
		}
		// used to show a transition conflict. This guard will simply deactivate one transition and thus
		// solve the conflict
		bool auto_start(cd_detected const&)
		{
			return false;
		}

		typedef player_ p; // makes transition table cleaner

		// Transition table for player
		struct transition_table : mpl::vector<
			//    Start     Event         Next      Action				 Guard
			//  +---------+-------------+---------+---------------------+----------------------+
			a_row < Stopped , play        , Playing , &p::start_playback                         >,
			a_row < Stopped , open_close  , Open    , &p::open_drawer                            >,
			_row < Stopped , stop        , Stopped                                              >,
			//  +---------+-------------+---------+---------------------+----------------------+
			a_row < Open    , open_close  , Empty   , &p::close_drawer                           >,
			//  +---------+-------------+---------+---------------------+----------------------+
			a_row < Empty , open_close  , Open    , &p::open_drawer2                            >,
			a_row < Empty   , open_close  , Open    , &p::open_drawer                            >,
			row < Empty   , cd_detected , Stopped , &p::store_cd_info   ,&p::good_disk_format  >,
			row < Empty   , cd_detected , Playing , &p::store_cd_info   ,&p::auto_start        > ,
			//  +---------+-------------+---------+---------------------+----------------------+
			a_row < Playing , stop        , Stopped , &p::stop_playback                          >,
			a_row < Playing , pause       , Paused  , &p::pause_playback                         >,
			a_row < Playing , open_close  , Open    , &p::stop_and_open                          >,
			//  +---------+-------------+---------+---------------------+----------------------+
			a_row < Paused  , end_pause   , Playing , &p::resume_playback                        >,
			a_row < Paused  , stop        , Stopped , &p::stop_playback                          >,
			a_row < Paused  , open_close  , Open    , &p::stop_and_open                          >
			//  +---------+-------------+---------+---------------------+----------------------+
		> {};
		// Replaces the default no-transition response.
		template <class FSM,class Event>
		void no_transition(Event const& e, FSM&,int state)
		{
			std::cout << "no transition from state " << state
				<< " on event " << typeid(e).name() << std::endl;
		}
	};
	// Pick a back-end
	typedef msm::back::state_machine<player_> player;

	//
	// Testing utilities.
	//
	static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused" };
	void pstate(player const& p)
	{
		std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
	}

	void test()
	{        
		player p;
		// needed to start the highest-level SM. This will call on_entry and mark the start of the SM
		p.start(); 
		// go to Open, call on_exit on Empty, then action, then on_entry on Open
		p.process_event(open_close()); pstate(p);
		p.process_event(open_close()); pstate(p);
		// will be rejected, wrong disk type
		p.process_event(
			cd_detected("louie, louie",DISK_DVD)); pstate(p);
		p.process_event(
			cd_detected("louie, louie",DISK_CD)); pstate(p);
		p.process_event(play());

		// at this point, Play is active      
		p.process_event(pause()); pstate(p);
		// go back to Playing
		p.process_event(end_pause());  pstate(p);
		p.process_event(pause()); pstate(p);
		p.process_event(stop());  pstate(p);
		// event leading to the same state
		// no action method called as it is not present in the transition table
		p.process_event(stop());  pstate(p);
		std::cout << "stop fsm" << std::endl;
		//p.stop();
	}
}

int test_in_main()
{
	test();
	return 0;
}